Wireless femtocell setup methods and apparatus

ABSTRACT

Methods and apparatus that enable a wireless femtocell to operate in its designated frequency so as to minimize interference between the wireless femtocell and neighboring base stations (and other femtocells or nomadic cells). In one exemplary embodiment, the femtocell cell comprises a UMTS (Universal Mobile Telecommunications System) femtocell which has the ability to scan the air interface in a manner similar to that associated with a UE in order to identify unallocated resources within the wireless network, and subsequently request access for the unallocated resources. Business methods useful in combination with the aforementioned methods and apparatus are also disclosed.

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BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates generally to the field of wirelesscommunication and data networks. More particularly, in one exemplaryaspect, the present invention is directed to the implementation of afemtocell radio frequency setup procedure so as to minimize interferencebetween other femtocells and/or base stations of the primary networkoperator.

2. Description of Related Technology

The deployment of additional base stations in a wireless network is aconsiderable capital expenditure for network operators. One proposedmethod of defraying the cost to a service provider is via user-initiateddeployment of small cellular base stations, which are commonly referredto as “femtocells”. The intended mode of operation for a femtocell is toaugment the service provider's existing network of base stations byconnecting to the service provider's network via a broadband interface(such as DSL or cable). Due to the smaller size and cost of a femtocell,they can be distributed in areas which are otherwise not feasiblyserviced through standard base station deployment (e.g., by extension ofindoor service coverage, or temporary service coverage).

Femtocells are far cheaper to manufacture than a typical base station,and possess simpler software. Femtocells are also typically not fullyfeatured, and cannot support the same number of users as a typical basestation. Furthermore, femtocells offer complete and self-containeddeployment. The relative cost and simplicity of operation allows anon-technical audience (i.e., residential and small business users) topurchase and operate femtocells. The benefits of femtocell deploymentare shared between the user and the network. For a user, as mentionedabove, the femtocell offers an inexpensive and easy method toselectively augment network coverage. Another distinct advantage offemtocells over other user managed ad hoc networks is their seamlessintegration with current network base stations, as opposed to theexpensive hardware and software costs necessary for multi-mode capabletransceivers.

Universal Mobile Telecommunications System (UMTS) and Femtocells—

The Universal Mobile Telecommunications System (UMTS) is an exemplaryimplementation of a “third-generation” or “3G” cellular telephonetechnology. The UMTS standard is specified by a collaborative bodyreferred to as the 3^(rd) Generation Partnership Project (3GPP). The3GPP has adopted UMTS as a 3G cellular radio system targeted for interalia European markets, in response to requirements set forth by theInternational Telecommunications Union (ITU). The ITU standardizes andregulates international radio and telecommunications. Enhancements toUMTS will support future evolution to fourth generation (4G) technology.

Currently, the standardization body for mobile communication (3GPP) isspecifying a new network femtocell element called a “Home Node B” (HNB).This is a modified Node B (aka, UMTS base station) designed for use inbuildings, with focus on home or residential environments, in order toincrease in-building coverage. For example, in one exemplary usage case,a user of a mobile phone might wish to augment their wireless coverageby implementing a HNB in their apartment. The user employs a DSLconnection to connect the HNB to the operator's Core Network. The usageis beneficial for both operator and user; i.e., the user may save money,improve data throughput, and conserve battery power for his mobile phone(by improved in-house coverage) when using his HNB. The operator getsadditional network coverage area; see, e.g., 3GPP TR 25.820, “3G HomeNode B Study Item Technical Report” v100 (Release 8), which isincorporated herein by reference in its entirety.

Flexibility of use is one important requirement for HNB operation. AnHNB should be easy to use, and easily transportable, so that it can beused nomadically; e.g., the user may operate it one day in hisapartment, and the next day on a business trip in a hotel. Additionallythe HNB may be switched on and off unpredictably; an example of sucherratic usage would be a user who does not operate the HNB at nightwhile he/she is asleep.

The simplicity of HNB operation, and convenience of setup for the homeuser, also creates some unique challenges for network operators. Priorto the deployment of femtocells, base station networks were planned anddeployed by a network operator, and were relatively static in nature.Physical network resources were also planned in advance by the basestation operator. Network access functions such as security andauthorization were easily controlled by a network operator through thebase station fixtures as well. The nomadic usage of HNBs hassignificantly complicated these fixed base station network operations.

One such example of increased network complexity is the allocation ofspectrum resources. Spectrum allocation is a major implementation issuefor carrier networks. A typical Node B installation is runningpermanently at a fixed location. Based on its fixed geography, theoperator allocates different radio resources (i.e., carrier frequenciesor codes) to neighboring Node Bs. The neighboring Node Bs' geographiclocations and distances are fixed; therefore radio frequency (RF)interference is minimized. Careful network planning is necessary,otherwise different UEs (User Equipment) connected to neighboring NodeBs may mutually interfere, and valuable spectrum resources inefficientlyutilized, thereby imposing costs on the operators of these networks.

Several solutions have been contemplated in the prior art to address theissue of network radio frequency spectrum allocation including frequencydetection, spectrum occupation (also referred to as free or usable), andspectrum selection. For example, U.S. Pat. No. 5,963,848 to D'Avelloissued Oct. 5, 1999 and entitled “Method and apparatus for assigning achannel to a mobile unit in a wireless communication system” discloses amethod and apparatus which determines which channels in a wirelesscommunication system are both authorized for cordless operation andavailable. A channel is then selectively chosen from this list to reducethe probability that an interferer will be on the chosen channel. Forexample, the channel could be randomly selected from all availablechannels or randomly selected from a limited group of available channelsto avoid co-channel interference. Alternatively, the channel could bechosen based upon the level of the signal that last caused that channelto be blocked. Finally, the channel could be chosen based upon thenumber of channels from an available channel to the nearest blockedchannel.

United States Publication No. 20040235428 to Nagai et al. published Nov.25, 2004 and entitled “Communication system, and endpoint device andinterrogator” discloses a communication system wherein each endpointdevice which has received an interrogating signal from an interrogatorresponds with a reflected signal generated by modulating theinterrogating signal with appropriate information. Each endpoint deviceincludes a distance detecting portion operable to detect a distancebetween the interrogator and the endpoint device; a reflecting portionoperable to receive and reflect the interrogating signal; an informationgenerating portion operable to generate replying information to betransmitted to the interrogator; a band determining portion operable todetermine on the basis of the detected distance a frequency band of amodulating signal used to modulate a reflected signal generated by thereflecting portion; and a modulating-signal generating portion operable,according to the replying information, to generate the modulating signalhaving a frequency within the determined frequency band. The distancedetecting portion may be provided in the interrogator, rather than inthe endpoint device. The frequency of the modulating signal may bedetermined on the basis of the number of the endpoint devices ready forcommunication with the interrogator, or a distribution of overallfrequency utilization ratio of the reflected signals received from theindividual endpoint devices.

United States Patent Publication No. 20060294573 to Rogers et al.published Dec. 28, 2006 and entitled “Media distribution system”discloses a system, apparatus, method and article to distribute mediainformation. The apparatus may include a transceiver to receive digitalinformation representing media information. The apparatus may furtherinclude a processor to couple to the transceiver, the processor toselect a modulation technique based on a receiver type and an ultra-highfrequency channel using a cognitive algorithm. The transceiver maytransmit the media information over the channel using the modulationtechnique.

German Publication No. DE4104890 to Dipling published Aug. 27, 1992 andentitled “Mobile radio telephone system—with disconnection of eachbattery-operated mobile station in traffic-free situation” discloses aradio telephone system that has each mobile frequency multiplex stationcoupled via a number of duplex speech channels with fixed stations,coupled to the telephone line network. The mobile stations exhibiting nocommunication traffic are cyclically disconnected and are switched backin via a time slot radio information signal transmitted by a fixedstation and containing the addresses of each mobile station identifiedby the incoming traffic within the time slot. A quitting signal isprovided for detecting the highest reception field strength to selectthe transmission path.

WIPO Publication No. 2003096590 to Logvinov et al. published Nov. 20,2003 and entitled “Method and System of Channel Analysis and CarrierSelection in OFDM and Multi-Carrier Systems” discloses a method tochannel estimation in OFDM systems. The embodiment of this invention isa block of new logic (16) and modifications performed to othercomponents of the system, added to any existing OFDM receiver, whichutilizes information available from other blocks as found in thereceiver. This logic (16) would improve the units' error rate because ofthe improved channel quality estimations it makes available. Thisimprovement is made possible because both channel noise data and channelsignal data (11) are used in the estimation process. This data goesthrough a learning process over time and multiple data blocks forfurther improvements in the quality of the estimate. This improvement ispossible without any direct communications with other remote units, butit could be used in a multi-node environment to improve the performanceof the system as the whole.

WIPO Publication No. WO/2007/093653 published Aug. 23, 2007 to Herraizet al., and entitled “Method and system for establishing a direct radiocommunication between two or more user devices in a cellular mobilecommunication system” discloses a method for establishing a direct radiocommunication between two or more user devices in a cellular mobilecommunication system, whereby said users are subscribed to the sameoperator. According to the invention, a cognitive radio technique isused to detect spectrum resources available for radio communications ina predetermined area containing said at least two user devices. Themethod is characterized in that it also includes the following steps inwhich: at least one resource is selected from the available resources,said resource being a resource of the operator common to the two or moreuser devices; and a direct radio link is established between said twousers using the detected free resource of the operator. The inventionalso relates to a system for establishing a direct radio communicationbetween two or more user devices in a cellular mobile communicationsystem.

European Publication No. EP1248477 to Zimmerman et al. published Oct. 9,2002 and entitled “Method and device for controlling dynamic frequencyselection within a wireless communication system” discloses a method ofcontrolling frequency selection within a wireless communication systemin response to radar-like interference signals which comprisescontinuously or quasi-continuously monitoring and assessing one or morefrequencies with respect to radar-like interference signals, allocatinga quality parameter to each assessed frequency, the quality parameterindicating a probability that a frequency is occupied, and selecting oneor more transmission frequencies in dependence on the allocated qualityparameters. Optionally, a further monitoring of one or more frequencieswith respect to at least one of the radar-like interference signals andother interference signals can be performed.

WIPO Publication No. WO2007040453 published Apr. 12, 2007 entitled“Automatic Configuration Of Pico Radio Base Station” discloses methodsand apparatus to configure a femto radio base station. A macro receiverof the femto radio base station is used to acquire detected coverageinformation of a radio access network. The detected coverage informationis used to determine an operation parameter for use by the macrotransceiver of the femto radio base station. In one embodiment, thedetected coverage information is transmitted to a control node of theradio access network. The control node determines the operationparameter and communicates the operation parameter to the femto radiobase station. The femto radio base station is accordingly configuredusing the operation parameter for further operation towards UEsaccessing the femto radio base station.

Other spectrum allocation schemes also exist in the prior art. Forexample, in the context of a wireless LAN (WLAN), WLAN Access Pointsscan the spectrum for electromagnetic interference and select a portionof spectrum with the lowest interference for transmission. The accesspoint independently decides what the optimal spectral usage is, based onthe used spectrum. A comparable solution is used in base stations forcordless telephones (e.g., DECT).

In addition to the above-described limitations of the prior art,standard UE operation cell selection procedures rely on the UE scanningfor, and finding the strongest cell. The cell selection is performed bythe UE, rather than the network. The UE informs the network about theselection and communication between the UE and the network proceedsnormally. One key difference between femtocell systems and prior artresource allocation methods is that prior art mobile communicationnetworks assume that the network controls all unused resources at agiven time. This is a valid assumption when the UE selects a specificcell for the request and the occupied resources are known by thenetwork. However, this assumption is not valid for resource allocationof a femtocell, in that the network does not know which resources areunused at the location of the femtocell when the femtocell makes aresource request. Furthermore, the network will generally not know theexact current position of the femtocell.

Therefore, despite the foregoing variety of different approaches tonetwork resource management, none of these solutions address theadditional complexity relating to spectrum allocation that occurs witharbitrary femtocell deployment. In the context of UMTS, the prior artsolutions are not usable for HNBs, as HNBs will be operated in alicensed spectrum. Spectrum usage must remain under the control of theoperator who owns and operates the licensed spectrum band. Therefore theallocation of spectrum resources to be used by HNBs must be performed inthe Core Network and controlled by the operator. Unfortunately, the RFenvironment at the location of the HNB is unknown by the Core Network.Accordingly, improved methods and apparatus for efficiently assigningspectrum usage are needed.

Such methods and apparatus would ideally provide a simple control schemefor the network operator to manage spectral resources, while alsomaintaining ease of use and transparent operation for a non-technicaluser. Such improved methods and apparatus would also aim to find anunused frequency resource at the location of the HNB for transmissionwith UEs. Advantageously, the network would select the resource to useby the HNB, with the HNB becoming an extension of the network's basestation capability.

SUMMARY OF THE INVENTION

The present invention satisfies the foregoing needs by providing, interalia, improved methods and apparatus for implementing a femtocell withina wireless network such as e.g., a 3G/UMTS cellular network.

In a first aspect of the invention, a method of operating a cell withina wireless network is disclosed. In one embodiment, the cell comprise anetwork connection with a core of the network, and the method comprises:scanning the network resources to identify at least a portion ofunoccupied network resources; requesting at least a portion of theunoccupied network resources from the core of the network; and occupyingthe at least a portion of unoccupied network resources after beinggranted the unoccupied resources by the core.

In one variant, the wireless network comprises a cellular network havinga plurality of base stations, and the cell comprises a cell having areduced set of capabilities as compared to that of one of the basestations. The cellular network comprises e.g., a UMTS-enabled network,and the cell comprises a femtocell.

In another variant, the act of scanning the network resources furthercomprises obtaining a plurality of initializing parameters. Theplurality of initializing parameters originates for example from anentity within the core of the network. Alternatively, the plurality ofinitializing parameters originates from a computer-readable mediainternal to the cell.

In yet another variant, the act of scanning the network resourcescomprises scanning only a subset of all resources associated with aselected network operator.

Alternatively, the act of scanning the network resources comprisesscanning all resources which may affect the operation of the cell.

In still another variant, the method further comprises storing acellular identification of a neighboring base station associated withthe at least a portion of occupied cellular network resourcesidentified. The neighboring base station may be designated a defaultbase station for example.

In a second aspect, a method of operating a cell within a cellularnetwork is disclosed. In one embodiment, the cellular network comprisesone or more base stations, and the method comprises: scanning a firstfrequency range of the cellular network; determining the strongest basestation transmission within the cellular network; decoding a signal fromat least one of the one or more base stations, the signal indicative ofa geographic location; reading data, the data correlating a defaultfrequency range with the geographic location; and determining a powersignal from one or more neighboring devices operating within the defaultfrequency range.

In one variant, the first frequency range is determined per a cellularnetwork standard.

In another variant, the method further comprises designating one of theone or more neighboring devices having the greatest power signal as adefault neighboring device.

In a further variant, the cell comprises a UMTS femtocell, and the datacomprises data stored locally to the femtocell.

In a third aspect of the invention, a femtocell capable of operatingwithin a wireless network is disclosed. In one embodiment, the femtocellcomprises: a processing device coupled to a memory; a wirelesssubsystem; a network interface subsystem in communication with a coreportion of the wireless network; and a plurality of executableinstructions resident within the memory. When executed by the processingdevice, the instructions perform the method comprising: initiating ascan via the wireless subsystem to determine wireless network resources;identifying at least a portion of unoccupied wireless network resourcesfrom the core portion via the network interface subsystem; receiving agrant message from the core portion granting access to the unoccupiedresources; and signaling the wireless subsystem to occupy at least aportion of the un-occupied wireless network resources.

In one variant, the cell comprises a UMTS femtocell, the wirelesssubsystem comprises a cellular air interface, and the network interfacesubsystem comprises a wired interface selected from the group consistingof (i) a DSL modem, (ii) a cable (DOCSIS) modem, and (iii) a T1 line.

In a fourth aspect of the invention, a method of operating a networkentity is disclosed. In one embodiment, the network entity is capable ofdirectly or indirectly controlling one or more base stations and one ormore femtocells within a wireless network, and the method comprises:allocating network resources to the one or more base stations; receivinga request from at least one of the one or more femtocells, the requestseeking permission to utilize at least a portion of the networkresources; and granting the request if it is determined that the networkresources allocated to the one or more base stations will not beadversely affected by the one or more femtocells utilizing the at leasta portion of the network resources.

In one variant, the method further comprises decoding a listing ofoccupied resources as detected by the one or more femtocells. Thewireless network comprises e.g., a cellular network, and the listing ofoccupied resources comprises one or more cellular entity identificationvalues. The one or more cellular entity identification values arefurther comprised of in one variant base station cellular entityidentification values and femtocell cellular entity identificationvalues, and the method further comprises reading from a memory a listingof allocated resources for the one or more cellular entityidentification values.

In another variant, the act of determining that the network resourcesallocated to the one or more base stations will not be adverselyaffected by the one or more femtocells utilizing the at least a portionof the network resources is based at least in part on minimizing radiofrequency interference (RFI) within the wireless network.

Alternatively, the act of determining that the network resourcesallocated to the one or more base stations will not be adverselyaffected by the one or more femtocells utilizing the at least a portionof the network resources is based at least in part on maximizing datathroughput within the wireless network.

As yet another alternative, the act of determining that the networkresources allocated to the one or more base stations will not beadversely affected by the one or more femtocells utilizing the at leasta portion of the network resources is determined based at least in parton providing a predetermined quality of service (QoS) level within thewireless network.

In another variant, the method further comprises denying the request ifit is determined that the network resources allocated to the one or morebase stations will be adversely affected by the one or more femtocellsutilizing the at least a portion of the network resources. The denialcomprises for example a denial message, the denial message furthercomprising a hold-off time indicative of a later period in time when asubsequent request may be sent.

In a fifth aspect of the invention, a method of doing businessassociated with a wireless network is disclosed. In one embodiment, thenetwork comprises a plurality of substantially fixed base stations, andthe method comprises: providing a plurality of substantially portablecells to respective ones of subscribers of the network, the plurality ofcells augmenting the coverage of the substantially fixed base stations;allocating network resources to at least one of the base stations;receiving a request from at least one of the cells, the request seekingpermission to utilize at least a portion of the network resources; andgranting or denying the request based at least in part on an evaluationof one or more profitability or revenue considerations relating to useof the at least portion of the network resources by the at least onebase station or the at least one cell.

In a sixth aspect of the invention, a computer readable apparatuscomprising a storage medium is disclosed. In one embodiment, the mediumcomprises a plurality of executable instructions which, when executed bya computer of a network entity capable of directly or indirectlycontrolling one or more base stations and one or more femtocells withina wireless network, perform the method comprising: allocating networkresources to the one or more base stations; receiving a request from atleast one of the one or more femtocells, the request seeking permissionto utilize at least a portion of the network resources; and granting therequest if it is determined that the network resources allocated to theone or more base stations will not be adversely affected by the one ormore femtocells utilizing the at least a portion of the networkresources.

Other features and advantages of the present invention will immediatelybe recognized by persons of ordinary skill in the art with reference tothe attached drawings and detailed description of exemplary embodimentsas given below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a typical prior art UMTS cellularnetwork, comprising Home Node B (HN) deployment within the network.

FIG. 1A is a simplified diagram of a typical prior art UMTS cellularnetwork cell comprising Home Node B deployment within the network cell.

FIG. 2 is a logical flow diagram illustrating one embodiment of ageneralized methodology for radio resource setup in accordance with theprinciples of the present invention.

FIG. 2A is a logical flow diagram illustrating one implementation of themethodology of FIG. 2, in the context of a 3G Home Node B system.

FIG. 2B is a logical flow diagram illustrating an exemplary methodologyfor the scanning of network radio resources in accordance with theprinciples of the present invention.

FIG. 3 is a graphical illustration of an exemplary RF setup procedurefor a UMTS cellular network HNB according to one embodiment of thepresent invention.

FIG. 3A illustrates an exemplary simplified RF setup procedure for aUMTS cellular network HNB in accordance with the principles of thepresent invention.

FIG. 3B is a logical flow diagram illustrating one embodiment of afrequency allocation methodology in accordance with the principles ofthe present invention.

FIG. 4 illustrates an exemplary femtocell apparatus useful forimplementing the aforementioned methodologies of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the terms “client device”, “end user device” and “UE”include, but are not limited to cellular telephones, smartphones (suchas for example an iPhone™), personal computers (PCs), such as forexample an iMac™, Mac Pro™, Mac Mini™ or MacBook™, and minicomputers,whether desktop, laptop, or otherwise, as well as mobile devices such ashandheld computers, PDAs, video cameras, set-top boxes, personal mediadevices (PMDs), such as for example an iPod™, or any combinations of theforegoing.

As used herein, the term “computer program” or “software” is meant toinclude any sequence or human or machine cognizable steps which performa function. Such program may be rendered in virtually any programminglanguage or environment including, for example, C/C++, Fortran, COBOL,PASCAL, assembly language, markup languages (e.g., HTML, SGML, XML,VoXML), and the like, as well as object-oriented environments such asthe Common Object Request Broker Architecture (CORBA), Java™ (includingJ2ME, Java Beans, etc.), Binary Runtime Environment (BREW), and thelike.

As used herein, the term “digital subscriber line” (or “DSL”) shall meanany form of DSL configuration or service, whether symmetric orotherwise, including without limitation so-called “G.lite” ADSL (e.g.,compliant with ITU G.992.2), RADSL: (rate adaptive DSL), VDSL (very highbit rate DSL), SDSL (symmetric DSL), SHDSL or super-high bit-rate DSL,also known as G.shdsl (e.g., compliant with ITU Recommendation G.991.2,approved by the ITU-T February 2001), HDSL: (high data rate DSL), HDSL2:(2nd generation HDSL), and IDSL (integrated services digital networkDSL), as well as In-Premises Phoneline Networks (e.g., HPN).

As used herein, the term “DOCSIS” refers to any of the existing orplanned variants of the Data Over Cable Services InterfaceSpecification, including for example DOCSIS versions 1.0, 1.1, 2.0 and3.0.

As used herein, the term “integrated circuit (IC)” refers to any type ofdevice having any level of integration (including without limitationULSI, VLSI, and LSI) and irrespective of process or base materials(including, without limitation Si, SiGe, CMOS and GaAs). ICs mayinclude, for example, memory devices (e.g., DRAM, SRAM, DDRAM,EEPROM/Flash, and ROM), digital processors, SoC devices, FPGAs, ASICs,ADCs, DACs, transceivers, memory controllers, and other devices, as wellas any combinations thereof.

As used herein, the term “memory” includes any type of integratedcircuit or other storage device adapted for storing digital dataincluding, without limitation, ROM. PROM, EEPROM, DRAM, SDRAM, DDR/2SDRAM, EDO/FPMS, RLDRAM, SRAM, “flash” memory (e.g., NAND/NOR), andPSRAM.

As used herein, the terms “microprocessor” and “digital processor” aremeant generally to include all types of digital processing devicesincluding, without limitation, digital signal processors (DSPs), reducedinstruction set computers (RISC), general-purpose (CISC) processors,microprocessors, gate arrays (e.g., FPGAs), PLDs, reconfigurable computefabrics (RCFs), array processors, secure microprocessors, andapplication-specific integrated circuits (ASICs). Such digitalprocessors may be contained on a single unitary IC die, or distributedacross multiple components.

As used herein, the terms “network” and “bearer network” refer generallyto any type of data, telecommunications or other network including,without limitation, data networks (including MANs, PANs, WANs, LANs,WLANs, micronets, piconets, internets, and intranets), hybrid fiber coax(HFC) networks, satellite networks, cellular networks, and telconetworks. Such networks or portions thereof may utilize any one or moredifferent topologies (e.g., ring, bus, star, loop, etc.), transmissionmedia (e.g., wired/RF cable, RF wireless, millimeter wave, optical,etc.) and/or communications or networking protocols (e.g., SONET,DOCSIS, IEEE Std. 802.3, 802.11, ATM, X.25, Frame Relay, 3GPP, 3GPP2,WAP, SIP, UDP, FTP, RTP/RTCP, H.323, etc.).

As used herein, the terms “network interface” or “interface” typicallyrefer to any signal, data, or software interface with a component,network or process including, without limitation, those of the Firewire(e.g., FW400, FW800, etc.), USB (e.g., USB2), Ethernet (e.g., 10/100,10/100/1000 (Gigabit Ethernet), 10-Gig-E, etc.), MoCA, Serial ATA (e.g.,SATA, e-SATA, SATAII), Ultra-ATA/DMA, Coaxsys (e.g., TVnet™), radiofrequency tuner (e.g., in-band or OOB, cable modem, etc.), WiFi(802.11a,b,g,n), WiMAX (802.16), PAN (802.15), IrDA or other wirelessfamilies.

As used herein, the term “wireless” means any wireless signal, data,communication, or other interface including without limitation Wi-Fi,Bluetooth, 3G (e.g., 3GPP, 3GPP2, and UMTS), HSDPA/HSUPA, TDMA, CDMA(e.g., IS-95A, WCDMA, etc.), FHSS, DSSS, GSM, PAN/802.15, WiMAX(802.16), 802.20, narrowband/FDMA, OFDM, PCS/DCS, analog cellular, CDPD,satellite systems, millimeter wave or microwave systems, acoustic, andinfrared (i.e., IrDA).

Overview

The present invention provides, inter alia, methods and apparatus thatenable a femtocell (such as a 3G HNB) to operate in a designatedfrequency band (e.g., a licensed band) without interfering withneighboring base stations (e.g., 3G Node Bs) or femtocells, oralternatively being interfered with by them.

In one exemplary embodiment of the invention, the femtocell comprises aHNB that has the ability to scan the air interface in a manner similarto that associated with a UE. The HNB scans for signals from neighboringNode Bs and HNBs (e.g., broadcasted system information, reference orsynchronization signals, etc.) to determine the occupied frequencyranges in the intended service area. In one variant of the exemplaryembodiment, the frequency range to scan is limited by the HNB based onpre-configuration and the current position of the HNB. In a UMTS system,the current position may be determined by decoding the broadcastedsystem information of surrounding Node Bs or HNBs. Therefore the HNB mayhave the ability to obtain location information (e.g., the ability toread the Mobile Country Code) from the broadcasted system information ofnearby Node Bs or HNBs.

In an alternate method, the HNB may obtain location information via itsbroadband connection, or yet another local or remote mechanism such as aGPS receiver, or even triangulation with known base stations.

Information generated by the aforementioned scanning procedure isformatted and/or translated, and transferred to a network (e.g., theCore Network of a UMTS system) as input for an allocation entity. Thisentity (e.g., a frequency allocation unit or FAU) determines thefrequency range acceptable for use by the HNB based on the scannedinformation. The scanned information may comprise for example a listingor translatable representation of unavailable resources. For instance,the scanned information may comprise a listing of unavailablefrequencies, or occupied frequency bands. In a UMTS system, the scannedinformation may also be represented as occupied cell IDs.

In one variant of the invention, a first phase is utilized whereininformation about the country where the device is located is gathered.This information is used to determine/limit the frequency regions toscan for occupation, and to advantageously enable operation in differentcountries. In a second phase, the measurement results from the firstphase are reported to the core network (e.g., FAU), which decides aboutthe resources which should be used by the HNB, and which transmits theappropriate parameters to the HNB.

In one embodiment, a centralized FAU is used to provide inter aliaunified management of network resources. A messaging system forcommunication between the FAU and HNBs is disclosed. The message systemcomprises a mechanism for issuing a request for resources, a report onunavailable resources, and an assignment of resource(s). Furthermore, amethod for storing to and reading from computer-readable medium (e.g., ahard-disk drive or other mass storage device of the HNB or networkentity) is disclosed, where the medium contains a correlation betweenknown cells (e.g., Node Bs and HNBs cell IDs) and occupied resources.

A setup procedure for the femtocell is also disclosed. In oneembodiment, this procedure comprises an initial scan, request forresources, and a subsequent assignment of resources. In one exemplaryvariant, the HNB powers on or is otherwise initialized (e.g., rebooted),and performs an initial scan. A request for a radio resource and theresults of this initial scan are communicated to the FAU. The FAUassigns the HNB a frequency resource based on, among other things, theresults of the HNB's scan. Moreover, this setup procedure may besimplified, if the conditions remain unchanged after the HNB is switchedoff and subsequently switched back on another time, as it is unnecessaryto obtain location information.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention are now described indetail. While these embodiments are primarily discussed in the contextof an HNB operating within a UMTS network, it will be recognized bythose of ordinary skill that the present invention is not so limited.Moreover, while discussed primarily in the context of communicationbetween a HNB and a dedicated FAU resident to the network operator, itis recognized that other implementations of mobile base stationfunctionality or spectrum management functionality could be implementedat other points within the network without departing from the spirit andscope of the present invention.

Network Architecture—

As is well known, a cellular radio system comprises a network of radiocells each served by a transmitting station, known as a cell site orbase station. The radio network provides wireless communications servicefor a plurality of transceivers (in most cases mobile transceivers suchas cellular telephones or “smartphones”). The network of base stationsworking in collaboration allows for substantially seamless wirelessservice which is greater than the radio coverage provided by a singleserving base station. The individual base stations are connected byanother network (in many cases a wired or millimeter wave network),which includes additional controllers for resource management, and insome cases access to other network systems (e.g., internets such as theInternet) or MANs/WANs.

In a UMTS system, a base station is commonly referred to as a “Node B”.The UMTS Terrestrial Radio Access Network (UTRAN) is the collective bodyof Node Bs along with the UMTS Radio Network Controllers (RNC). The userinterfaces to the UTRAN via User Equipment (UE), which in many typicalusage cases comprises the aforementioned cellular phone or smartphone.FIG. 1 illustrates an exemplary UMTS cellular system 100. The UMTSsystem 100 comprises a plurality of base stations 101 (Node Bs) that areset at various fixed geographic locations. Each of these base stations101 are characterized by their respective wireless coverage areas 102. Acentralized management facility (i.e., the “Core Network” 103) generallygoverns the operation of the base station towers 101. Also depicted inFIG. 1 are HNBs 111, which are not necessarily geographically fixed.These HNBs 111 create wireless coverage areas 112 that may overlap withthose of other HNBs or Node Bs, as shown. Each of the HNBs 111 is indata communication with the FAU 104, which is part of the Core Network103, via an interface such as a broadband connection (e.g., DSL, DOCSIScable modem, MoCA interface, or even WiFi or WiMAX wireless interface).For simplification, only the FAU 104 entity is explicitly shown in theCore Network 103, but nevertheless the HNBs 111 are typically connectedto other entities located in the Core Network 103 as well.

FIG. 1A is a simplified diagram of a UMTS Cellular System illustratingan exemplary Node B 101A that has a coverage area 102A. Exemplary HomeNode B 111A has a coverage area 112A which is surrounded by or subsumedwithin the coverage area of Node B 102A, and neighbored by another HomeNode B 111B having its own coverage area 112B. Node B 101A transmitssystem information periodically or continuously; e.g. the cell ID. Also,the neighboring Home Node B 111B transmits its corresponding systeminformation in similar fashion. As shown in FIG. 1A, the entirety ofHome Node B's 111A coverage area 112A, lies within the coverage area ofNode B 102A. Furthermore, a portion 120 of the coverage area 112Aoverlaps with the coverage area 112B of the other HNB, as shown.

In this exemplary usage scenario, without proper spectrum managementtechniques, the addition of Home Node B 111A will mutually interferewith one or more of Node B 101A and the other HNB 111B.

As previously stated, in the exemplary context of UMTS, one requirementof operation is that the spectrum usage must always remain under thecontrol of the operator who owns the licensed spectrum band. To satisfythis requirement, the FAU entity 104 within the Core Network 103 isresponsible for managing radio resources. Because of the unpredictableand non-linear nature of the radio environment, a centralized entitywill not have the complete information necessary to most efficientlyassign radio resources. Therefore, the presently disclosed systemcomprises a centralized FAU 104 working with HNBs 111 that can scan, aswell as report on, their radio environment. The FAU and HNBs utilize inone embodiment a request-grant type protocol for allocating radioresources, although it will be appreciated that other protocols oraccess/allocation schemes may be used. Accordingly, the architecturesshown in FIGS. 1 and 1A ensure that the network operator has ultimatecontrol over spectrum allocation, while still being able to adjust forthe HNB localized radio environment.

Methods—

Referring now to FIG. 2, a generalized setup procedure for allocatingnetwork resources for a network entity in communication with a femtocellis illustrated.

As shown in FIG. 2, the exemplary method 200 comprises the femtocell(s)in question first scanning known resources (step 202) in order toidentify those that are unused or available. Once these unused resourceshave been identified (step 204), they are assigned to the femtocell(s)in question per step 206.

Referring now to FIG. 2A, one exemplary implementation of thegeneralized methodology of FIG. 2 (in the context of a 3G Home Node B)is described.

The femtocell is first powered on and internal settings within thefemtocell are initialized. The initialization of internal settings maygenerally include booting the software, as well as any resetting ofhardware settings within the femtocell itself. During initialization,the femtocell also establishes a network connection with the networkentity. This may comprise negotiating and establishing a connection overthe access medium of choice; e.g., DSL over copper wire, FIOS, cablemodem, etc. Upon establishing the network connection, the femtocellnotifies the network entity of its presence and optionally itsoperational status. In order to perform this step, one embodiment of thefemtocell retrieves from a computer-readable media (e.g., HDD, ROM orflash memory) the address and protocol for connecting to the networkentity. In one variant, this comprises use of a TCP/IP transport overthe aforementioned access medium, although other transports andprotocols may be used with equal success.

At step 210, the femtocell obtains any parameters which it requires toinitiate a scan of the resources. The parameters may originate fromeither the (remote) network entity, or alternatively may be retrievedinternally from computer-readable media (e.g., file, look-up table,etc.) present within the femtocell itself. In other embodiments, acombination of entities could be used to initialize the scanningparameters (e.g., receiving location identification from the networkentity as well as looking up scan parameters from an internal memorylocal to the femtocell). In the exemplary embodiment, similar to UMTS UEoperation, these parameters are located locally to the femtocell and areread from a computer readable media.

At step 212, the femtocell scans resources based on its initial scanparameters in order to determine currently occupied resources. In thescan, the femtocell may scan only a subset of all resources (e.g., onlythe resources used by a preferred network operator, portion of anetwork, portion of the resource “space” such as a fraction of afrequency spectrum, a certain frequency range at a certain time instancewith a certain spreading code, etc.), or may perform a full scan of allresources which may affect femtocell operation. For a UMTS system, thescanning procedure is preferably separated into multiple stages, as isbest illustrated in FIG. 2B. At step 222 of FIG. 2B, the femtocellbegins scanning a first frequency range; e.g., corresponding to the UMTSstandard. After determining the strongest base station transmission at224, the femtocell decodes the mobile country code at step 226. At step228, the femtocell uses the mobile country code to reference aninternally stored table, and then establishes a default frequency rangefor future scans at step 230. At step 232, the femtocell uses thedefault frequency range to determine the received power of allneighboring femtocells and base stations, optionally with a preferenceto a given service provider.

At step 214 (FIG. 2A), the femtocell identifies the occupied resourcesand determines what unused (or under-utilized) resources are availablefor the femtocell. Each neighboring base station or femtocell which hasa received power (as measured by the femtocell or its proxy) greaterthan a specified threshold is identified by that femtocell. In oneembodiment, the corresponding Cell IDs for such cells are utilized as anidentifier. In one variant of the foregoing methodology, the basestation with the greatest received power level is stored (via e.g., itsCell ID) as a default base station. This default base stationdesignation will be useful in, inter alia, later initializationsequences to determine if the femtocell has changed locations (recallthat base stations are fixed geographically, whereas femtocells are notso constrained).

Next, at step 216, the femtocell issues a request for an unused resourcefrom the network entity. In one embodiment, the femtocell transmits alist of one or more Cell IDs to the network entity using theaforementioned network connection. The network entity can then use thelocalized information provided by the femtocell as an input to resourceassignment. Other schemes may be used as well.

At step 218, the network entity assigns a resource to the femtocell.During this step, other necessary control modifications for setup may berequired. For instance, the network entity may explicitly signalparameters for the femtocell to be used thereby (e.g., carrierfrequency, spreading or access code, bandwidth and Cell ID, etc.).

At step 220, the femtocell uses the parameters from the network entityto set up its transceiver. In a UMTS system, this process includesbroadcasting control channel data, and monitoring the receiver forincoming connection requests.

UMTS System Methods

Referring now to FIG. 3, the steps of the methodology of FIGS. 2-2A aredescribed in terms of an exemplary sequence of UMTS-specific steps. FIG.3A illustrates a simplified version of the setup procedure of FIG. 3.

At step 301, the HNB 111A (see FIG. 1A) is switched on, and establishesa secure connection to the Core Network 103, via a wired broadband basedaccess.

When an HNB powers on, a security procedure is automatically executedfor the HNB to correctly operate within the cellular network. Someminimal requirements are imposed, comprising IP security,authentication, and authorization. IP security must be established forbearer traffic to be carried over an untrusted or public network such asthe Internet. Authentication and registration with the Core Networkensure that the HNB is a valid device. Lastly, the HNB must beauthorized to provide service through the service provider. It will beappreciated that other security measures known to those of ordinaryskill in the art may be employed as well including e.g., encryption ofall or a portion of the data being transmitted so as to protect dataconfidentiality, and cryptographic residue (hash) generation to provideintegrity protection.

In one exemplary embodiment, the secondary (e.g., wired) interface isimplemented as a DSL connection, although any interface providing accessto the Core Network control entities could be used, such as e.g., aDOCSIS cable modem, T1 line, wireless interface (e.g., WiMAX or WiFi),Ethernet (802.3), and so forth. The interface uses a standard TCP/IPtransport/network layer scheme across the connection to access the CoreNetwork. Furthermore, the UMTS standard defines protocols that guaranteesecure transport of signaling and user traffic over IP. The messaginginvolved for authentication comprises the HNB sending a request foraccess to the Core Network. This request may include a form ofidentification and/or proof of identification, in the form of usernameand password or security certificate (e.g., digital signature) providedby the HNB. After the exchange of authentication information (the HNBmust also verify the Core Network is legitimate), the Core Networkregisters the presence of the HNB.

At step 302, the HNB 111A scans the designated (e.g., UMTS-designated)frequency band to identify nearby cells using its last known parameters.In a UMTS system, the Broadcast Control Channel (BCCH) is broadcastconstantly from the base station 101. The BCCH is a unidirectionalchannel which carries information necessary for identifying andinitiating a communication channel to the base station. The BCCHtransmit power is constant, but environmental factors may affect signalreception (RF interference, geography, weather-induced or Rayleighfading, etc.). Therefore, received signal strength of the BCCH can beused as a rough estimation of proximity. Parameters that are transmittedon a UMTS BCCH may comprise: a listing of frequencies, cell ID, powercontrol and discontinuous transmission (DTX) information. Also, thePublic Land Mobile Network ID (PLMN) to which that cell belongs isencapsulated in the system information transmitted on the BCCH. The PLMNID is a concatenation of the Mobile Country Code (MCC) with the MobileNetwork Code (MNC) and Location Area Identity (LAI), although it will berecognized that these protocols are merely exemplary in nature, andothers may be used consistent with the invention.

During this step 302, the HNB 111A scans for broadcast control channelsof any surrounding cellular stations; the HNB uses internally storedparameters for carrier frequency, codes and bandwidth based on the lastknown location (MCC). If no carrier is found using this focused or“intelligent” approach, the HNB must in effect perform a “brute force”search with broader parameter searches until it finds a BCCH signalwhich meets the signal to noise (SNR) ratio threshold requirement.

At step 303, the HNB 111A decodes the BCCH of the strongest celllocated. After decoding the strongest Node B's Mobile Country Code, theHNB can derive preferred parameters for its home operator (or roamingoperator), using the aforementioned parameter lookup table. The Cell IDof the transmitting base station 101A is also encapsulated within theBCCH.

If the parameters of the current MCC differ from the last knownparameters, then the HNB 111A assumes that its location has changed. TheHNB proceeds to step 304, to initiate a rescan of broadcast controlchannels.

If the BCCH decode of the strongest cell yields a different Cell ID fromthe “Default Cell ID”, then the HNB 111A assumes that its location haschanged, and must proceed to step 304.

If the BCCH decode of the strongest cell yields a Cell ID which matchesthe “Default Cell ID”, then the HNB 111A assumes that its location hasnot changed. The HNB proceeds to step 306. At this point, a simplifiedprocedure may be followed (the HNB has determined that it has notmoved). One exemplary embodiment of such a simplified procedure isillustrated in FIG. 3A.

At step 304, the HNB 111A has determined that its location has changed.The HNB updates its parameters using the current MCC to reference aparameter lookup table.

At step 305, the HNB 111A performs a “clean” scan for broadcast controlchannels of any surrounding cellular stations, using the updatedparameters for carrier frequency, codes and bandwidth based on the newknown location (MCC).

At step 306, the HNB 111A decodes all received Cell IDs of neighboringHNBs 111B and Node Bs 101A. If the strongest Cell ID matched the“Default Cell ID”, then the HNB proceeds to store the updated Cell IDsof all other neighboring cells (e.g., to a computer readable media suchas a HDD or memory), and continues to step 308. If the strongest Cell IDdid not match the “Default Cell ID”, then the HNB proceeds to step 307.

At step 307, the HNB 111A stores the strongest Cell ID found to avariable “Default Cell ID”. Additional parameters referenced by the“Default Cell ID” may also be stored for use in the initial power upsequence. One exemplary case of an additional stored referencedparameter is “Default Frequency Range”.

At step 308, the HNB 111A transmits a request for radio resource to theFAU 104, via the Core Network 103. The message RESOURCE_REQ includes alisting of cell IDs of neighboring stations, identified in step 306. Inanother embodiment, to maintain compatibility with other systems, theRESOURCE_REQ message may be separated into two or more separatemessages; e.g., one for a resource request, and another messagedetailing the list of cell IDs detected. The FAU may or may not send anacknowledgement.

At step 309, the FAU 104 selects a resource for assignment to therequesting HNB. One embodiment of the selection process is described ingreater detail below.

At step 310, the FAU 104 transmits a grant for radio resource. Themessage RESOURCE_GRANT includes an assignment of resources, comprisingcarrier frequency, code, bandwidth, and cell ID. In another embodiment,to maintain compatibility with other systems, the RESOURCE_GRANT messagemay be separated into a plurality of separate messages. The HNB 111A mayor may not send acknowledgement.

At steps 303 and 306, the HNB 111A behavior is triggered by thestrongest Cell ID found. In some embodiments, the HNB may decode aplurality of the Node B Cell IDs, so as to minimize “false” triggering,when the HNB is located on overlapping cell boundaries. In a variant ofthis plural Cell ID trigger, signal strength for each correspondingpermanent Node B fixture is also recorded, along with Cell ID at step307.

While the aforementioned steps are discussed in an initial scan, singleresource request-and-grant method, a similar method may be used wherebythe HNB 111A may request a resource multiple times. In one such case,the HNB may request a resource, but the FAU does not assign a resourcedue to network burden or other prevailing operation or business-relatedcondition. In this case, a hold-off time and denial would be returnedwith a RESOURCE_DNY command. The HNB would then hold off for a specifiedtime before re-requesting a radio resource; this type of resource andgrant may or may not necessitate re-initiating a radio frequency scan.The hold-off interval need not be deterministic; for example, a(pseudo)randomized back-off value may be generated for each suchmessage; that way, multiple HNBs requesting resources would back off forrandom periods of time, thereby avoiding collisions or inundating theFAU with simultaneous requests. Myriad other back-off/multiple accessschemes will also be recognized given the present disclosure.

In another such embodiment, scanning of radio frequency could occurmultiple times. In this embodiment, a “super” HNB may control two ormore resources. Such a super HNB could poll for resources. For instance,an HNB capable of occupying more than one radio resource could scanradio resources periodically (i.e., polling), and request additionalresources when it determines that a neighboring HNB has powered down,and/or vacated a resource. These requests could be either a plurality ofseparate RESOURCE_REQ requests, or they could be a single RESOURCE_REQrequest with an additional field specifying the number of resourcesrequested.

In another variation, scanning of radio frequency could occur based on amessage originated at the FAU 104. This FAU initiated scan attempt maybe used to reinitiate a previously denied service. For instance, the FAUmay log the Cell IDs of surrounding HNBs 111B for an HNB 111A that hasbeen denied service. When a neighboring HNB 111B powers down, the FAUmay initiate a radio scan at the previously denied HNB 111A to determineif the HNB 111A can be enabled with the neighboring HNB's 111B recentlyvacated resource.

Frequency Allocation Unit Operation—

Referring now to FIG. 3B, the operation of the exemplary embodiment ofthe FAU at step 309 above (FAU radio resource selection process) is nowdescribed in greater detail.

At step 350, the FAU 104 has received the request for a radio resource.The FAU 104 decodes the listing of occupied resources as detected by theHNB 111A. In the exemplary UMTS system, this listing comprises a listingof Cell IDs. The listing of decoded Cell IDs is separated into Cell IDsof Node B(s) 101A and Cell IDs of HNB(s) 111B. The Cell IDs of Node B(s)101A are assumed to be a permanent fixture of the HNB's 111Aenvironment, and will not change. The Cell IDs of neighboring HNB(s)111B are assumed to be temporary fixtures of the HNB's 111A environment,and may change nomadically, erratically, periodically, or not at all.

At step 351, the FAU 104 retrieves from storage corresponding resourcespreviously assigned to each Cell ID. In a UMTS system, these resourcesmay comprise a listing of bandwidth, frequency bands (channel numbers),code rates, etc.

At step 352, the FAU 104 proceeds to select available radio resources.Several criteria for radio resource selection are available, and aremoderated by the network operator. Such criteria may include for exampleminimizing radio frequency interference, maximizing data rates,minimizing data rates/bandwidth consumption, supporting varying levelsof quality of service (QoS) for various users, maintaining certainsecurity requirements, etc. Additionally such criteria may be dependantfrom the contract between the HNB operator/owner and the operator of thecellular network. For example, a femtocell with a low-budget tariff(e.g., residential) obtains a smaller bandwidth compared to a femtocellwith a business tariff for, e.g., an office building. In one example, alimited data pipe shared between Node Bs 101 and HNBs 111 in a regionmay be preferentially served to Node Bs 101, therefore HNBs 111 may beassigned resources to support high data rates, only during periods oflow network usage. In another example, the FAU 104 may determine that aparticular Cell ID of a Node B 101 has too many HNBs 111 in itsvicinity, the FAU 104 may opt to deny service to additional HNBs 111which request a frequency in that Node Bs 101 vicinity.

At step 353, the FAU 104 generates a response to the HNB 111. Thisresponse may be either a grant of resources, or a denial of resources.In a grant of resources, the HNB 111 is assigned an appropriate cell ID,a frequency band, code, etc. In a denial of service the FAU 104 maysimply return a denial, or in another embodiment, the denial message mayinclude a hold-off time, such that the HNB 111 may request access at ascheduled later time.

At step 354, The FAU 104 updates its internal table or other datastructure with the new HNBs 111 Cell ID, and radio resources. For an HNB111 which was denied service, the FAU 104 may opt not to record itsentry. The FAU 104 may also record the denied HNB 111 along with a timestamp, or number indicating number of denials (for use in algorithmsensuring fair HNB service). The FAU 104 may also record the denied HNB111 and any neighboring HNB cell IDs, such that when a neighboring HNB111 is powered down, the denied HNB 111 may be offered service.

Femtocell Apparatus

Referring now to FIG. 4, exemplary femtocell apparatus 400 useful inimplementing the functionality previously described above is illustratedand described. The femtocell apparatus 400 comprises one or moresubstrate(s) 416 that further include a plurality of integrated circuitsincluding a processing subsystem 409 such as a digital signal processor(DSP), microprocessor, gate array, or plurality of processing componentsas well as a power management subsystem 415 that provides power to thefemtocell 400.

The processing subsystem 409 might comprise in one embodiment aninternal cache memory 409A, or a plurality of processors (or amulti-core processor). The processing subsystem 409 is preferablyconnected to a non-volatile memory 410, as well as a memory subsystem413. The memory subsystem 413 may implement one or a more of DMA 413Atype hardware, so as to facilitate rapid data access.

The exemplary apparatus 400 will, in some embodiments, implement someform of broadband access. In the illustrated embodiment, the broadbandaccess is provided by a DSL connection. Hence, a DSL analog baseband411, DSL line driver 412 and DSL line filter 414 are shown. The digitalportion of DSL processing may either be performed in the processor 409,or alternatively in a separate DSL processor (not shown). Further, whilea DSL broadband connection is illustrated, it is recognized by one ofordinary skill that other broadband access schemes such as DOCSIS cablemodem, T1 line, etc. could be readily substituted or even used in tandemwith the aforementioned DSL interface.

The exemplary apparatus comprises two RF modem subsystems. The BTS modemsubsystem 420 enables the femtocell to search neighboring BTS RFtransmissions. The UE modem subsystem 430 enables the femtocell toprovide service to UEs.

The BTS modem subsystem 420 comprises a digital baseband 407, analogbaseband 405, and RF components for RX 401 and TX 402. It is recognizedthat in some embodiments that it may be desirable to obviate some of thecomponents presently illustrated (such as RF TX 402), or alternatively,the discrete components illustrated may be merged with one another toform a single component (such as merging RF RX 401 and RF TX 402,).

The UE modem subsystem 430 comprises a digital baseband 408, analogbaseband 406, and RF components for RX 403 and TX 404. While a single RX403 TX 404 is illustrated between the exemplary femtocell apparatus 400and a UE, it is appreciated that multiple UE RF front ends may exist tosupport multiple simultaneous UEs and air interfaces, or alternativelyimplement MIMO aspects of operation such as for example that describedin co-owned and co-pending U.S. patent application Ser. No. 12/150,485filed Apr. 28, 2008 entitled “Apparatus and Methods for Transmission andReception of Data in Multi-Antenna Systems”, incorporated herein byreference in its entirety.

In one exemplary implementation, the femtocell apparatus disclosed abovefurther comprises apparatus for scanning for the received signal powerof different types of mobile communication systems. Accordingly, theapparatus responsible for detecting signal power (e.g., RSSI) mustreceive the radio frequency signal and at least partially demodulateneighboring cell broadcasted control channels. In one exemplaryembodiment, the femtocell fully demodulates the downlink power signalfrom the cellular network. Alternatively, for a wireless system whichdoes not require full demodulation to extract the Cell ID, the signalscan be demodulated only as far as is required to extract the receivedCell ID.

In some wireless networks, pre-configuration data is required in orderto complete the demodulation process. In one such exemplary embodiment,this demodulation data is referenced to location identification. In anexemplary embodiment, the femtocell obtains an ID of the country inwhich the scanned mobile communication system is running (e.g. themobile country code or MCC) via the wireless interface. Alternatively,in another embodiment, the femtocell selects a set of parameters from astored table or a hard-coded set of parameters.

The femtocell should also be able to seamlessly operate with a networkentity as well as a Core Network. In one such embodiment, the femtocelland network entities are connected via a broadband type access. Suchbroadband type access allows the Core Network to control licensedspectral usage. Therefore, if the femtocell is unable to operate withthe resources specified by the resource allocation message, thefemtocell must desist from receiving and transmitting.

FAU Apparatus

Implementation of the frequency allocation unit (FAU) 104 unit may beaccomplished in hardware and/or software. The functionality of the FAU104 may be implemented as a separate entity in the Core Network 103, orthe functions may be included in other existing Core Network entitiessuch as a Serving GPRS Support Node (SGSN). In the exemplary embodimentdescribed subsequently herein, the FAU entity is implemented withinsoftware embodied in a computer readable medium (e.g., HDD, memory,etc.) and executable by a processing device (e.g. a digital processor,microprocessor, etc.).

The FAU 104 must obtain and/or store a table of currently used resources(e.g. frequency, bandwidth, code, etc.) with the ID of the cell thatuses it (e.g. the Cell ID). Other data, specific to a particular HNB111, but relevant for system management, may also be stored to media forusage by the FAU 104. Furthermore, while the present embodiment suggeststhe storage of data local to the FAU functionality, it is appreciatedthat remote storage of the data may be utilized as well.

Furthermore, it is understood that multiple methods for obtainingcurrently used resources may be utilized. For example these methods mayinclude periodic refresh and reclamation procedures. Reclamation ofvaluable spectrum may be critical for nomadic femtocell operation wherethe previously assigned femtocell may experience, e.g. a “dirty” poweroff sequence.

The FAU 104 must select a free resource within the range of resourcesassigned for dedicated use by the operator and to consider informationfrom the received resource request (e.g. a requested bandwidth) for thisselection. While in an exemplary embodiment, the primary input forresource allocation is from the HNB 111, it is appreciated that otherinputs may be necessary and further may override the HNB 111 resourcerequest. In certain circumstances, the FAU 104 may determine that theHNB 111 resource request is to be ignored, and no such resource isallocated to the HNB 111. Such a circumstance may occur due to networkburden, business accounting, improper/unsupported hardware, security,etc. Furthermore it is appreciated that the resource pool selected fromby the FAU 104 may not be a comprehensive pool of resources (suchlimitations may be imposed for hardware/software compatibility issues,security issues, business issues etc.).

Business Methods and Rules Engine

It will be recognized that the foregoing network apparatus andmethodologies may be readily adapted to various business models. Forexample, in one such model, a service provider/network operator mayprovide an enhanced-capability femtocell (such as that describedpreviously herein) to customers willing to pay a premium, or as anincentive for its higher-tier customers.

In another paradigm, certain strategic users could be selected toreceive such enhanced-capability femtocells based on inter alia theirsubscription level, rate of usage, geographic location, etc., even inexchange for consideration from the network operator (e.g., a rebate orreduction of their monthly service fees if they operate the femtocell inaccordance with the network provider policies).

The aforementioned network apparatus and methodologies may also bereadily adapted for operation in accordance with an underlying businessrules “engine”. This business rules engine may comprise for example asoftware application and/or hardware, and is implemented in oneembodiment as a separate entity at the Core Network, or alternativelywithin an existing entity residing at the Core Network or other networkmanagement process.

In one embodiment, the business rules engine takes into account therevenue and/or profit implications associated with providing resourcesto one or more user-operated femtocells so that the resource allocationto the femtocell does not negatively impact network user experience, orthe services that are able to be provided to users on the network viathe geographically fixed base stations. Accordingly, the exemplarybusiness rules engine can modify the behavior of the system at specificsteps described in the methodologies above in order to accomplish one ormore economic objectives for the network operator. For instance, in oneexample, evaluation of the request from a femtocell for resources (e.g.,frequency spectrum) may include an analysis of the incremental cost,revenue, and/or profit associated with the various allocation options(i.e., allocation to the requesting femtocell, or denial of the requestand allocation to another femtocell, or a static base station). These“business rules” may be imposed e.g., at time of resource request andthen maintained for a period of time (or until an event triggering are-evaluation occurs), or alternatively according to a periodic model.In another variant, the party who owns the resources is tasked withmaking business-related decisions; i.e., the network operator for thebusiness relationship between the femtocell (owner) and the corenetwork.

As yet another alternative, the femtocell may be equipped with logic(e.g., a business rules engine or component thereof, such as a clientportion of a distributed application) that is configured to analyze andmake business or operational decisions relating to the business modelbetween the client device (e.g., UE) and the femtocell. For instance,the femtocell may preferentially process or allocate resources tocertain requesting users based on their status (e.g., as existingsubscribers of the service provider associated with the core network,the type of service requested and revenue/profit implications associatedtherewith, etc.)

Myriad different schemes for implementing dynamic allocation ofresources will be recognized by those of ordinary skill given thepresent disclosure.

It will be recognized that while certain aspects of the invention aredescribed in terms of a specific sequence of steps of a method, thesedescriptions are only illustrative of the broader methods of theinvention, and may be modified as required by the particularapplication. Certain steps may be rendered unnecessary or optional undercertain circumstances. Additionally, certain steps or functionality maybe added to the disclosed embodiments, or the order of performance oftwo or more steps permuted. All such variations are considered to beencompassed within the invention disclosed and claimed herein.

While the above detailed description has shown, described, and pointedout novel features of the invention as applied to various embodiments,it will be understood that various omissions, substitutions, and changesin the form and details of the device or process illustrated may be madeby those skilled in the art without departing from the invention. Theforegoing description is of the best mode presently contemplated ofcarrying out the invention. This description is in no way meant to belimiting, but rather should be taken as illustrative of the generalprinciples of the invention. The scope of the invention should bedetermined with reference to the claims.

1.-28. (canceled)
 29. A method of operating a cell of a cellular network, the cellular network comprising one or more base stations, the method comprising: scanning a first frequency range of the cellular network; determining a strongest base station transmission within the cellular network; decoding a signal from the strongest base station transmission, the signal indicative of a geographic location; scanning a second frequency range of the cellular network, the second frequency range correlated with the geographic location; and determining a signal power of at least one base station transmitting within the second frequency range of the cellular network.
 30. The method of claim 29, wherein the first frequency range is determined per a cellular network standard.
 31. The method of claim 29, further comprising designating one of the at least one base station having a greatest value of the determined signal power as a default neighboring base station.
 32. The method of claim 29, wherein the cell comprises a Universal Mobile Telecommunications System (UMTS) femtocell, and the data comprises data stored locally to the femtocell.
 33. A non-transitory computer readable apparatus comprising a storage medium having instructions configured to administer a first wireless femtocell, the instructions further configured to, when executed by a computer: scan a first frequency range of a cellular network; determine a strongest base station transmission within the cellular network; decode a mobile country code (MCC) of the base station emitting the strongest base station transmission; use the mobile country code to reference a default frequency range for future scans within a specific geographic location; and determine a signal power from each of the one or more base stations operating within the default frequency range.
 34. The non-transitory computer readable apparatus of claim 33, wherein the first femtocell scans the first frequency range to determine one or more occupied frequency ranges.
 35. The non-transitory computer readable apparatus of claim 33, wherein the first frequency range is determined per a cellular network standard.
 36. The non-transitory computer readable apparatus of claim 35, wherein the first frequency range corresponds to a frequency range specified in a Universal Mobile Telecommunications System (UMTS) standard.
 37. The non-transitory computer readable apparatus of claim 33, wherein the first frequency range is limited by pre-configuration of the femtocell.
 38. The non-transitory computer readable apparatus of claim 33, wherein the first frequency range is limited by the specific geographic location of the femtocell.
 39. The non-transitory computer readable apparatus of claim 33, further comprising instructions wherein preference is given to a specific service provider when determining the signal power.
 40. The non-transitory computer readable apparatus of claim 33, further comprising instructions to designate one of the one or more base stations operating within the default frequency range, having the greatest signal power, as a default base station.
 41. The non-transitory computer readable apparatus of claim 33, further comprising instructions wherein data identifying the default base station is stored within the first wireless femtocell.
 42. The non-transitory computer readable apparatus of claim 33, further comprising instructions wherein the default base station is used to determine if the first wireless femtocell has changed locations.
 43. A method of operating a first base station within a cellular network, the cellular network comprising a plurality of base stations, the method comprising: determining one or more occupied frequency ranges within the cellular network; scanning a first of the one or more occupied frequency ranges within the cellular network; based at least in part on the scanning, determining a strongest base station transmission; decoding a signal from the strongest base station transmission, the signal indicative of a geographic location; reading data, the data correlating a default frequency range with the geographic location; and determining a signal power from each of the one or more base stations operating within the default frequency range.
 44. The method of claim 43, wherein the first frequency range is determined per a cellular network standard.
 45. The method of claim 43, wherein the first frequency range is limited by the pre-configuration or geographic location of the strongest base station transmission.
 46. The method of claim 43, further comprising designating one of the one or more base stations operating within the default frequency range having the greatest signal power as a default base station.
 47. The method of claim 43, further comprising storing data identifying the default base station within the first base station.
 48. The method of claim 43, further comprising using the default base station to determine if the first base station has changed locations. 